The present invention relates to a method and apparatus for controlling a door moving distance passed by an opening and closing door of an automatic door during the period when the door reaches the highest speed starting from its stop condition, a door moving distance passed by the door during the period when the door is braked and stopped starting from the condition where the door is opening or closing at the highest speed, or a total door moving distance passed by the door during the period when the door is braked and reversed to the opposite direction and then reaches the highest speed starting from the condition where the door is opening or closing at the highest speed, by regulating torque of the door opening and closing motor.
In an automatic door, a belt is engaged with a drive pulley that is driven by a motor and a driven pulley, a door is connected to this belt, and the door operates to open or close by driving the motor into normal rotation or into reverse rotation. For instance, as shown in FIG. 8, at a closing stop point if a human body detection signal is input to a control unit of the automatic door, the door is accelerated from a stop condition up to the highest speed, then while maintaining that speed the door operates to open at the highest speed up to an opening deceleration point, when the door has reached the opening deceleration point it is decelerated until it stops, and thereafter it operates again to open at a low speed until it reaches an opening stop point.
Then, after the door has been kept still for a predetermined period of time at the opening stop point, it begins to move in the closing direction and is accelerated up to the highest speed, then while maintaining that speed it operates to close at the highest speed up to a closing deceleration point, when it has reached the closing deceleration point, it is decelerated until it stops, and thereafter it operates to close at a low speed up to a closing stop point.
On the other hand, the automatic door is designed such that if the door detects a passing body such as a human body or it collides against a passing body when it is operating to close at the highest speed, then the door immediately operates to open at the highest speed, in other words, it performs a reversing operation.
While the automatic door performs an accelerating operation from a stop condition until the highest speed is attained, a decelerating operation by braking, and reversing a operation for moving a door in the opposite direction after braking as described above, if a door moving distance L.sub.1 passed by the door during acceleration is too short, then the door abruptly reaches the highest speed and hence "hiccup phenomena" (unsmooth movements) would occur upon starting of the door, on the contrary if the door moving distance L.sub.1 is too long, then the operation of the door would become slow and dull, and therefore, it is necessary to select the door moving distance L.sub.1 upon acceleration to an optimum distance by adjusting the weight of the door, a running resistance and the like.
Also, if a door moving distance L.sub.2 passed by the door during deceleration is too short, then the door would be braked abruptly and hence "hiccup phenomena" (unsmooth movements) would occur or abnormal forces would act upon various portions of the door; resulting in damages, whereas if the door moving distance L.sub.2 is too long, then the operation of the door would become slow and dull, and therefore, it is necessary to select the door moving distance L.sub.2 upon deceleration also to an optimum door moving distance by adjusting a weight of the door, running resistance and the like.
Furthermore, during reversing operation when the door has collided against a passing body, it is necessary to quickly decelerate and stop the door and thereafter immediately accelerate it up to the highest opening speed.
As described above, it is necessary to control the torque of a door opening/closing motor so that a door moving distance passed by the door when the door is accelerated or decelerated during accelerating operation, decelerating operation or reversing operation, may become an optimum distance.